Radial or taintor gates cover relatively large flow areas. Thus, a relatively small opening movement of a radial gate passes a relatively large volume of water to flow through the opening. This is true because the control of the opening movement of a radial gate is extremely difficult. Thus, it is the usual practice of utilizing butterfly valves or other types of valves in conjunction with radial gates to control the flow of water passed through the radial gate to a turbine. These valves are costly to manufacture and install and also operate normally in a full open position or a full closed position. Thus, the valve size is critically related to the synchronous speed of the turbines.